Plate-type heat pipe

ABSTRACT

A plate-type heat pipe includes a top cover, a bottom cover, a first wick structure and a second wick structure. The bottom cover hermetically contacts with the top cover to form a container. A plurality of working fluid is contained in the container. The bottom cover has a heat absorbing plate. The first wick structure is adhered to inner surfaces of the top and bottom covers. The second wick structure is sandwiched between the top and bottom covers. Top and bottom ends of the second wick structure abut against the inner surface of the top cover and a central portion of the heat absorbing plate of the bottom cover. An area of the bottom end is smaller than that of the heat absorbing plate.

BACKGROUND

1. Technical Field

The present disclosure relates to heat pipes and, more particularly, to a plate-type heat pipe having a good heat dissipation efficiency and a stable and reliable performance.

2. Description of Related Art

Generally, plate-type heat pipes efficiently dissipate heat from heat-generating components such as a central processing unit (CPU) of a computer. A conventional plate-type heat pipe comprises a container, a continuous wick structure adhered to an inner surface of the container, and a working fluid contained in the container. Because a space between electronic components is narrow, the plate-type heat pipe is thin. When a bottom of the container absorbs heat of the electronic component, the working fluid located at a lower portion of the container is vaporized and moves to an upper portion of the container; at the upper portion of the container, the vaporized working fluid is cooled to a condensed working fluid. However, during the vaporized working fluid rushing up to the upper portion of the container, the vaporized working fluid may impact and disperse the condensed working fluid. Thus, a speed of the condensed working fluid flowing back to the bottom of the container decreases. The plate-type heat pipe is prone to be dried.

What is needed, therefore, is a plate-type heat pipe having a good heat dissipation efficiency and a stable performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-section view of a plate-type heat pipe in accordance with a first embodiment of the present disclosure.

FIG. 2 is a cross-section view of a second wick structure of a plate-type heat pipe in accordance with a second embodiment of the present disclosure.

FIG. 3 is a cross-section view of a second wick structure of a plate-type heat pipe in accordance with a third embodiment of the present disclosure.

FIG. 4 is a cross-section view of a second wick structure of a plate-type heat pipe in accordance with a fourth embodiment of the present disclosure.

DETAILED DESCRIPTION

Referring to FIG. 1, it illustrates a plate-type heat pipe in accordance with a first embodiment of the present disclosure. The plate-type heat pipe comprises a bottom cover 10, a top cover 30, a continuous first wick structure 50, and a second wick structure 70. The bottom cover 10 and the top cover 30 form a hermetical container. A plurality of working fluid is contained in the container. The first wick structure 50 is adhered to an inner surface of the container. Opposite ends of the second wick structure 70 abut against the top cover 30 and the bottom cover 10.

The bottom cover 10 has a bowl-shaped configuration and is a metallic sheet. The bottom cover 10 comprises a bottom plate 11 and two sidewalls 13 extending perpendicularly and upwardly from opposite ends of the bottom plate 11. The bottom plate 11 comprises an elongated heat absorbing plate 113 and two extending plates 115 extending outwardly from opposite ends of the heat absorbing plate 113. The heat absorbing plate 113 is below the extending plates 115. The sidewalls 13 extend perpendicularly and upwardly from the extending plates 115. The top cover 30 is flat and hermetically contacts with the sidewalls 13. The continuous first wick structure 50 is adhered to inner surfaces of the bottom cover 10 and the top cover 30.

The first wick structure 50 comprises two first wick portions 51 adhered to the inner surface of the top cover 30 and a second wick portion 53 adhered to the inner surface of the bottom cover 10. The two first wick portions 51 respectively extend inwardly from two ends of the inner surface of the top cover 30 to a central portion of the inner surface of the top cover, inner ends of the two first wick portions 51 space from each other. The second wick portion 53 comprises two first wick sections 531, two second wick sections 533 and two third wick sections 535. The two first wick sections 531 are adhered to an inner surface of the heat absorbing plate 113 and respectively extend inwardly from two ends of the inner surface of the heat absorbing plate 113 to a central portion of the inner surface of the heat absorbing plate 113; inner ends of the two first wick sections 531 space from each other. The second wick sections 533 are adhered to inner surfaces of the extending plates 115. The third sections 535 are adhered to corners defined by the sidewalls 13 and the extending plates 115. The third wick sections 535 full with the corners. A thickness of the first wick section 531 is thinner than that of the second wick section 533. Thus, the working fluid contained in the first wick section 531 is vaporized from the first wick section 531 easily. A thickness of the third section 535 is larger than that of the second section 353. A cross-section of the third section 535 is a triangle and the thickness of the third section 535 decreases from a central portion to opposite ends.

The second wick structure 70 is located at a central portion of the plate-type heat pipe and opposite ends thereof abut against the central portion of the inner surface of the top cover 30 and the central portion of the inner surface of the heat absorbing plate 113 of the bottom plate 11 of the bottom cover 10. The second wick structure 70 has a bugle-shaped configuration and a width of the second wick structure 70 decreases from top to bottom. The second wick structure 70 communicates with the first wick structure 50. An area of a bottom end of the second wick structure 70 which contacts with the heat absorbing plate 113 is smaller than that of the heat absorbing plate 113.

When the plate-type heat pipe is used, the work fluid is vaporized. The vaporized work fluid rushes up to a top portion of the plate-type heat pipe and rushes to opposite ends of the plate-type heat pipe. The vaporized work fluid can not arrived at the corners formed by the sidewalls 13 and the extending plates 115 of the bottom plate 11 of the bottom cover 10 and the central portion of the plate-type heat pipe. The third wick sections 535 of the first wick structure 50 full with the corners to guide the condensed working fluid of opposite ends of the first wick structure 50 back to the heat absorbing plate 113 quickly. The second wick structure 70 fulls with the central portion of the plate-type heat pipe to guide the condensed working fluid of a central portion of the first wick structure 50 back to the heat absorbing plate 113 quickly and don't change a path of the vaporized work fluid.

Referring to FIG. 2, it illustrates a second wick structure 70 a of a plate-type heat pipe of a second embodiment of the present disclosure. A difference between the second wick structures 70, 70 a is that a through hole 71 is defined at a central portion of the wick structure 70 a from top to bottom. The through hole 71 communicates the central portion of the inner surface of the top cover 30 and the central portion of the inner surface of the heat absorbing plate 113 of the bottom plate 11. The through hole 71 has a bugle-shaped configuration and a width thereof decreases from top to bottom.

Referring to FIG. 3, it illustrates a second wick structure 70 b of a plate-type heat pipe of a third embodiment of the present disclosure. A difference between the second wick structures 70, 70 b is that the second wick structure 70 b is cylindrical.

Referring to FIG. 4, it illustrates a second wick structure 70 c of a plate-type heat pipe of a fourth embodiment of the present disclosure. A difference between the second wick structures 70 b, 70 c is that a through hole 73 is defined in a central portion of the second wick structure 70 b from top to bottom. A cross section of the through hole 73 is rectangular. The through hole 73 communicates the central portion of the inner surface of the top cover 30 and the central portion of the inner surface of the heat absorbing plate 113 of the bottom plate 11.

It is to be understood, however, that even though numerous characteristics and advantages of the disclosure have been set forth in the foregoing description, together with details of the structure and function of the disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A plate-type heat pipe comprising: a top cover; a bottom cover hermetically contacting with the top cover to form a container, a plurality of working fluid contained in the container, the bottom cover having a heat absorbing plate; a first wick structure adhered to inner surfaces of the top and bottom covers; and a second wick structure sandwiched between the top and bottom covers, top and bottom ends of the second wick structure abutting against the inner surface of the top cover and the inner surface of the heat absorbing plate of the bottom cover, respectively; wherein an area of the bottom end of the second wick structure is smaller than that of the heat absorbing plate.
 2. The plate-type heat pipe as claimed in claim 1, wherein the second wick structure has a bugle-shaped configuration and a width of thereof decreases from top to bottom.
 3. The plate-type heat pipe as claimed in claim 2, wherein a through hole is defined in a central portion of the second wick structure from top to bottom.
 4. The plate-type heat pipe as claimed in claim 1, wherein the second wick structure is cylindrical.
 5. The plate-type heat pipe as claimed in claim 4, wherein a through hole is defined in a central portion of the second wick structure from top to bottom.
 6. The plate-type heat pipe as claimed in claim 1, wherein the first wick structure has two first wick portions respectively extending inwardly from two ends of the inner surface of the top cover to a central portion of the inner surface of the top cover, inner ends of the two first wick portions spaced from each other and a second wick portion mounted on the inner surface of the bottom surface.
 7. The plate-type heat pipe as claimed in claim 6, wherein the bottom cover comprises two extending plates extending outwardly from opposite ends of the heat absorbing plate and located at above of the heat absorbing plate, the second wick portion comprises two first wick section adhered to an inner surface of the heat absorbing plate and respectively extending inwardly from two ends of the inner surface of the heat absorbing plate to a central portion of the inner surface of the heat absorbing plate, inner ends of the two first wick sections spaced from each other.
 8. The plate-type heat pipe as claimed in claim 7, wherein opposite ends of the second wick structure abut against the central portion of the inner surface of the top cover and the central portion of the inner surface of the heat absorbing plate.
 9. The plate-type heat pipe as claimed in claim 7, wherein the first wick section is thinner than the second wick section.
 10. The plate-type heat pipe as claimed in claim 7, wherein the bottom cover further comprises two sidewalls extending upwardly from the two extending plates and support the top cover, two third wick sections extending outwardly from the two second wick sections full with two corners defined by the sidewalls and the extending plates of the bottom cover.
 11. The plate-type heat pipe as claimed in claim 10, wherein a cross section of the third section is triangle and thickness of the third section decreases from a central portion to opposite ends. 